Biological waste treatment, biodegradative processes

Biodegradative Processes and Biological Waste Treatment Ana sis and Control... 

Some aspects of these concerns, such as the question of biodegradability of NTA and its heavy metal complexes, are beyond the scope of this text. However, NTA appears to be biodegradable in secondary, biological, waste treatment processes. The concerns dealing with complexation will be examined here. 

From all the information in the literature it can be concluded that conventional aromatic polyesters used up to now for technical purposes are not subject to a biologically induced degradation at a reasonable degradation rate. This excludes such polyesters from applications in biological waste treatment processes (composting) or which use biodegradability as a new material property for novel polymer applications, (e.g., controlled release of active substances in agriculture). 

Under the label of bioremediation, the use of microbial processes to destroy hazardous wastes has been the subject of intense investigation in the waste-treatment community for a number of years. Doubts still exist about claims for its effectiveness in a number of applications. It must be kept in mind, however, that there are many factors that can cause biodegradation to fail as a treatment process. Often physical conditions are such that mixing of wastes, nutrients, and electron acceptor species (such as oxygen) is too slow to permit biodegradation to occur at a useful rate. Low temperatures may make reactions too slow to be useful. Toxicants, such as heavy metals, may inhibit biological activity, and some metabolites produced by the microorganisms may be toxic to them. 

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